This invention relates to a device for preventing a tightened drum head fixing bolt from being loosened.
A drum head is provided at the upper and/or lower end of the drum body of a percussion musical instrument drum. A drum head fixing hoop is provided around the outer peripheral part of the drum head. The hoop on one end of the drum body is compressively tightened toward the other end of the drum body by screwing a bolt that engages the hoop into a lug nut which is supported on a lug that is fixed to the drum body and this fixes the drum head to the drum body and tensions the drum head.
The bolt fixes the drum head to the drum body and adjusts the tension of the drum head to tune its sound. However, the tightening bolt can be loosened by the vibration of the beating of the drum head for a long period of time. This will change the tension adjustment of the drum head.